Heat-Related Deaths in NYC May Increase with Climate Change

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Heat-related deaths in New York City's borough of Manhattan may
rise about 20 percent over the next decade, according to a new
study.

Researchers at Columbia University in New York analyzed the
relationship between daily temperatures and temperature-related
deaths across all seasons between 1982 and 1999 in Manhattan,
which comprises the most densely populated county in the United
States. The findings were published online May 19 in the journal
Nature Climate Change.

Using projections from 16 global climate models, the scientists
found that the number of heat-related deaths in the city could
increase by 20 percent by the 2020s, and in some worst-case
scenarios, could rise by 90 percent or more by the 2080s, said
study co-author Patrick Kinney, an environmental scientist at the
Mailman School of Public Health at Columbia University. [ Top
10 Surprising Results of Global Warming ]

To make their estimates, Kinney and his colleagues used the 1980s
as a baseline, during which about 370 Manhattan residents died
yearly from overheating. With this figure as a reference, a 20
percent increase could mean 74 additional yearly heat-related
fatalities in Manhattan by the 2020s.

"What we found was that there could be some benefits, in terms of
reduced fatalities in the wintertime because of warmer
temperatures, but our analysis suggests that those benefits are
outweighed by extra fatalities that will occur in the hotter
times of the year," Kinney told LiveScience.

Mercury rising

Daily readings in Manhattan's Central Park demonstrate that
average monthly temperatures have increased 3.6 degrees
Fahrenheit (2 degrees Celsius) between 1901 and 2000. Last year
was the
warmest year on record in Manhattan, and projections predict
rising temperatures over the next six decades, the researchers
said.

"The warming that's anticipated from climate change is happening
throughout the year, so the months that are already hot — like
June, July and August — are going to get hotter, but months that
are more moderate, like May and September, may become
uncomfortably hot or fatally hot," Kinney explained.

In their study, Kinney and his colleagues applied climate models
to two scenarios: one that assumed rapid global population growth
with limited efforts to control emissions, and another that
assumed
slower population growth combined with technological advances
to decrease emissions by the year 2040.

The researchers found that both projections pointed to increases
in temperature-related fatalities.

"It was a little surprising that no matter which climate model we
used, and which scenario of greenhouse gases we used, they all
consistently showed this effect of increasing fatality risk in
the future," Kinney said.

More of the same

And Manhattan is not alone, Kinney added. The trend toward more
fatalities is also expected for other cities, particularly in the
northern United States.

"Climate models of future temperatures do vary a bit from place
to place, but generally the story is pretty much the same,"
Kinney said.

The effects are not limited to cities, but heat waves are
typically more severely felt in densely populated areas. This is
because cities tend to concentrate heat, with buildings and
pavement surfaces soaking up heat during the day and releasing it
at night, the researchers said.

"This serves as a reminder that heat events are one of the
greatest hazards faced by urban populations around the globe,"
study co-author Radley Horton, a climate scientist at Columbia
University, said in a statement.

The way of the future

The researchers acknowledge uncertainties in their projections,
including that heat's effects could be made better or worse with
changing demographics, and how fatalities may be prevented with
better infrastructure or public policies.

Still, the findings suggest that cities and governments need to
do more to address the potential dangers posed by heat waves,
said Richard Keller, an associate professor of medical history
and bioethics at the University of Wisconsin-Madison, who was not
involved with the study.

"We have needed to rethink the dangers of heat for years," Keller
told LiveScience. "The
Chicago heat wave of 1995, and especially the European heat
wave of 2003 both caused catastrophic excess mortality."

Major federal programs provide heating assistance in the winter,
but there is no concomitant program for cooling assistance in the
summer, Keller said.

Kinney said that to combat the effects of deadly heat waves,
cities can open community cooling centers, plant trees or
construct "green" roofs.

The new findings demonstrate the importance of developing
strategies to adapt to future higher temperatures.

"Heat is a major and often underestimated killer," Keller said.
"While we evacuate in the face of hurricanes and floods, we tend
to ignore extreme heat, with deadly consequences. The 2003 heat
wave killed nearly 15,000 people in France alone — eight times
the mortality associated with Hurricane Katrina."